WO 2009/101148 A1 relates to an escalator or a moving walkway with two directions of travel comprising a step or pallet belt which is reversed in two reversing areas averted from each other. A device for monitoring the presence of steps or pallets of the step or pallet belt is provided, which device has at least one first detector provided for a detection function in the first direction of travel, and at least one second detector provided for the same detection function in the second direction of travel. The first and the second detector are in operative connection with an evaluation and control electronics unit which stops the drive of the escalator or of the moving walkway when missing steps or pallets are detected within the step or pallet belt. The evaluation and control electronics unit compares the signals of the first and second detector having an identical detection function for the different directions of travel in order to derive a signal for stopping the escalator or moving walkway therefrom.
DE 100 27 490 A1 discloses a safety device for escalators or moving walkways. The device is formed by at least one initiator operating in a non-contacting manner, which initiator is in operative connection with an evaluation and control electronics unit which stops the drive of the escalator or moving walkway when missing steps or pallets are detected within the step or pallet belt.
KR 10-20000014497 A discloses a monitoring device for an escalator. A motor, which can be triggered, and which is in operative connection with a transmission for moving a step belt, is monitored via a CPU.
DE 198 49 238 C1 discloses a method for shutting off passenger transport installations by monitoring functional units for malfunctions by means of control elements and combining them in the form of a signal to a safety chain. The signals of the functional units together with those from the drive monitoring unit are fed to at least one pre-control unit before the shut-off signal is fed to the shut-off contact of the drive or drives in dependence on the malfunction of the respective functional unit and/or drive monitoring unit.
It is generally known that drive motors are in immediate operative connection with transmission elements for driving a step or pallet belt, wherein the drive motor is often arranged between the reversing elements of the step or pallet belt.
It is also known that drive motors are positioned outside of the step or pallet belt, if required in connection with a transmission, and that the drive performance of the drive motor is transmitted to the step or pallet belt of the escalator or moving walkway via a drive means, for instance a chain or a belt.